Answer:
0.30625 Ci
Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 5.73E3 years
Original activity (Nₒ) = 0.350 Ci
Time (t) = 1.719E4 years
Difference in activities =?
Next, we shall determine number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 5.73E3 years = 5.73×10³ years
Time (t) = 1.719E4 years = 1.719×10⁴ years
Number of half-lives (n) =?
n = t / t(½)
n = 1.719×10⁴ / 5.73×10³
n = 3
Thus, 3 half-lives has elapsed.
Next, we shall determine the activity after 1.719E4 years. This can be obtained as follow:
Original activity (Nₒ) = 0.350 Ci
Number of half-lives (n) = 3
Activity remaining (N) =?
N = 1/2ⁿ × Nₒ
N = 1/2³ × 0.350
N = 1/8 × 0.350
N = 0.125 × 0.350
N = 0.04375 Ci
Finally, we shall determine the difference in activities. This can be obtained as follow:
Original activity (Nₒ) = 0.350 Ci
Activity remaining (N) = 0.04375 Ci
Difference in activities =?
Difference in activities = Nₒ – N
Difference in activities = 0.350 – 0.04375
Difference in activities = 0.30625 Ci.
Copper roofs on houses form patina (copper carbonates) over the course of years due to the reaction with oxygen, carbon dioxide and water in the air. Which of the following statements is incorrect for this process?
A) The reaction has a low activation energy.
B) The reaction has a low reaction rate.
C) The formation of patina would occur faster during the summer than the winter.
D) The formation of patina would occur slower at higher altitudes due to lower concentration of reactant. E) Adding a catalyst would increase the rate of patina formation.
Answer:
The answer is "Choice A".
Explanation:
In this question, the choice A is wrong because when the copper panels on houses produce a patina (copper oxide) through occur as a consequence of reactions from oxygen and water in the air, these reaction does not have low activation energy because lower activation energy that is stored in a faster response rate.
Measurements show that unknown compound has the following composition: element mass 62.1 % carbon, 10.5 % hydrogen and 27.6 % oxygen. Write the empirical chemical formula of this compound?
Answer:
C3H6O
Explanation:
The percentage composition of the elements in the compound are given as follows:
62.1 % carbon = 62.1g of C
10.5 % hydrogen = 10.5g of H
27.6 % oxygen = 27.6g of O
Next, we convert each mass to mole by dividing by their molar/atomic mass
C = 62.1/12 = 5.175mol
H = 10.5/1 = 10.5mol
O = 27.6/16 = 1.725mol
Next, we divide each mole value by the smallest mole value (1.725)
C = 5.175mol ÷ 1.725 = 3
H = 10.5mol ÷ 1.725 = 6.086
O = 1.725mol ÷ 1.725 = 1
The empirical ratio approximately of C:H:O is 3:6:1, hence, the empirical formula is C3H6O
WILL GIVE BRAINLIEST!!!!
Any type or form of energy can change into any other type of energy. This is referred to as _____.
A. energy transformations
B. law of conservation of mass
C. law of conservation of energy
D. mechanical energy
Answer:
C
Explanation:
The Law of Conservation of energy is that energy can be transformed from one form to another, but can be neither created or destroyed.
helppp nowwww plsss!!!
Answer:
it is D
Explanation:
A tree for one is a renewable resource, but. It said "farmed trees" therefore the best way to farm trees it well, to farm them. But to sustainably farm them you would need to replace what you destroyed to be able to keep farming in the future.
Answer:
New trees are planted to replace those that are cut down is the correct answer.
have a nice day! (^o^)
Please help!!! Is the following example of synthesis? 2H2 + O2 —> 2H2O
Answer:
hahahaa i can get the points
Explanation:
yes it is again LOL thanks
1.The splitting of a heavy, unstable nucleus into two lighter nuclei is called _____.
a. Fission
b. Fusion
c. Radioactive Decay
d. Isotopes
Answer:
A) Fission
Explanation:
Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.
Imagine that each of the three containers in Model 2 contains krypton atoms. The atomic radius of a krypton atom is 88.00 pm. Assuming the atom is a solid sphere, calculate the volume of one krypton atom in liters.
Answer:
The volume of a krypton atom in liters = 2.86 x 10⁻²⁷ liters
Explanation:
The volume of a sphere is given by the formula below:
V = 4/3 (π)(r³)
where π = 22/7, radius of the krypton atom = 88.00 pm
However, 1 picometre (pm) = 1 x 10⁻¹⁰ cm, converting 88.00 pm to cm will be:
88.00 pm x 10⁻¹⁰ cm/ 1 pm = 88.00 x 10⁻¹⁰ cm
Substituting the values above in order to determine the volume of a krypton atom:
V = 4/3 x (22/7) x (88.00 x 10⁻¹⁰ cm)³
V = 2.86 x 10⁻²⁴ cm³
However, 1000 cm³ = 1 liter
Therefore, 2.86 x 10⁻²⁴ cm³ in liters will be:
2.86 x 10⁻²⁴ cm³/ (1000 cm³/1 liter) = 2.86 x 10⁻²⁷ liters
The volume of a krypton atom in liters = 2.86 x 10⁻²⁷ liters
Thermal Energy Transfer Lab Edge
2021
help
please
Explanation:
same✊ raaaate meee please
HELP
NOW
Balance this equation: C2H5OH(1)+O2(g)—> CO2(g)+H2O(g)
Answer:
C2H5OH +O2(g)_CO2(g)+H2O(g) (unbalanced)
C2H5OH +3O2(g)_2CO2(g)+3H2O(balanced)
What is the capillary rise of ethanol in a glass tube with a 0.1 mm radius if the surface tension of ethanol is 0.032Jm2 and the density of ethanol is 0.71gcm3
Answer:
Explanation:
Expression for capillary rise is as follows
h = 2T / ρ g r where T is surface tension , ρ is density of liquid and r is radius of capillary tube.
T = .032 J m⁻²
ρ = .71 g / cm³
= 7100 kg / m³
r = .1 x 10⁻³ m = 10⁻⁴ m
h = 2 x .032 / (7100 x 9.8 x 10⁻⁴ )
h = .0092 m
= 9.2 mm .
Describe how to calculate the Rf value for a spot on a TLC plate.
Answer:
In thin-layer chromatography, the retention factor (Rf) is used to compare and help identify compounds. The Rf value of a compound is equal to the distance traveled by the compound divided by the distance traveled by the solvent front (both measured from the origin).
Which element would have similar properties to Sulfur? Chlorine O a ob Fluorine Oxygen Nitrogen
Answer:
sir/ma'am, i know i'm a NOOB at this kind of stuff but i believe it's oxygen.
Explanation:
i can't really remember the answer since it's been a week or so that i done this problem, it's between nitrogen and oxygen, though, i believe it's oxygen.
if ya don't believe me or trust me, then here's the link to help ya:
https://socratic.org/questions/what-elements-would-have-similar-properties-to-sulfur#628367
Many factors would bring advantages when using fuel cells in cars but which factors present a drawback?
Answer:
B. hydrogen storage
Explanation:
Answer: B hydrogen storage
Explanation:
correct on edge 2020
how many atoms are in 2.00 moles of Helium
Answer:
maybe try 4.002602, good luck
Please hurry I'm in a test... 50 pts :)) HIGH SCHOOL CHEMISTRY
Reactant P contains 50 J of energy, and reactant Q contains 35.3 J of energy. The reactants combine to form product PQ, which contains 104 J of energy. What is the energy transformation?
Energy is absorbed because the product has more energy than the reactants have.
Energy is absorbed because the product has less energy than the reactants have.
Energy is lost because the product has more energy than the reactants have.
Energy is lost because the product has less energy than the reactants have.
Answer:
A. Energy is absorbed because the product has more energy than the reactants have.
Here the energy of both reactants is combined together and not released.
Account for the difference in the shape and color of the potential maps for ammonia and the ammonium ion.
Answer:
Explained below.
Explanation:
The difference between the two of them will be considered from their electrostatic potential maps.
First of all the major difference is that ammonia molecule(NH3) has a lone lone pair of electron on the N atom.
Due to the this lone pair of electron on the N - atom of ammonia, it's bond angle will be slightly lesser than that of ammonium ion.
Therefore, In the electrostatic potential map of NH3, the charge distribution will not be symmetrical for the fact that there is electron rich N atom and so the N atom will be more red than the 3 hydrogen atoms (H atoms).
Whereas, the electrostatic potential map of NH4+ (ammonium ion) will be symmetrical due to the even/symmetrical distribution of all the 4 hydrogen atoms surrounding the central Nitrogen atom.
Also, the Nitrogen atom here in ammonium ion will have a lower electron density than the Nitrogen atom that's present in ammonia molecule due to the bonding existing between the lone pair electron and the Hydrogen atom
How many molecules are in 1.50 moles of hydrogen?
Answer:9.03*10^23
Explanation:
7. What is the maximum amount of NaCl that can be
dissolved (in 100g of water) at 90°C?
Answer:
Maximum amount of NaCl that can be Dissolved in 100g of water at 90'C
Explanation:
In fact, you can expect to be able to dissolve no more than 40 g of sodium chloride per 100 g of water at 80∘C . So, at 80∘C , you will have an unsaturated solution if you dissolve less than 40 g of sodium chloride, and a saturated solution if you dissolve about 40 g of sodium chloride
Answer:
The maximum amount of NaCl that can be Dissolved in 100g of water at 90'C
Explanation:
In fact, you can expect to be able to dissolve no more than 40 g of sodium chloride per 100 g of water at 80∘C . So, at 80∘C, you will have an unsaturated solution if you dissolve less than 40 g of sodium chloride, and a saturated solution if you dissolve about 40 g of sodium chloride.
helpppp nowwww plsss!!
Answer:
A
Explanation:
if the earth slows down then that will give more time to the sun meaning days/nights will be longer
24. According to the author, the term avant-garde
most nearly means:
F. a particular art movement founded
internationally in the early 1900s.
G, a form of painting and sculpture
associated primarily with France.
H. art that is not the standard of the time.
J. art that has modernist roots.
Iron is a transition element. transition elements that make them different from non-transition metals
such as magnesium.
Answer:
Transition metals differ from the non-transition metals such as magnesium in the following ways;
They have variable oxidation statesFormation of complex ions.Formation of colored ions.Transition metals both in the elemental and compound forms can serve as catalysts.Explanation:
Transition elements comprise of those elements in the d-block of the periodic table and which have incompletely-filled d-orbitals.
The transition elements are all metals and has the characteristic physical properties of metals such as;
high melting and boiling points,good conductors of heat and electricity,metallic lusterhigh densitiesmalleability and ductilityHowever, their chemical properties differ from those of the non-transition metals such as magnesium in the following ways;
They have variable oxidation states - the transition metals exhibit variability in their oxidation states because of the close similarity in the energies of the 4s and 3d electrons which are available for bond formation. For example, while magnesium has only one oxidation state of +2, vanadium a transition metal can have oxidation states of +2, +3, +4 and +5.Formation of complex ions - A complex ion consists of a central metal atom or ion to which several other atoms, ions or molecules are bonded. For example, blue tetramine copper (ii) ion, [Cu(NH₃)]²⁺.Formation of colored ions - unlike non-transition metal ions, the ions of transition metals are usually colored. For example, Copper (ii) ions, Cu⁺ are blue, Chromium (ii) ions, Cr³⁺, are green, etc.Transition metals both in the elemental and compound forms can serve as catalysts. For example, finely divide nickel serves as a catalyst in the hydrogenation of vegetable oil to margarine, while vanadium (v) oxide serves as a catalyst in the contact process for the manufacture of tetraoxosulfate (i) acid.can someone please help me!
Answer:
Explanation:
C defo
the electron configuration of an element in its ground state is illustrated above. which, if any, of the three principles that determine the most stable electron configuration of an element does this configuration disobey
Answer:
hello your question is incomplete attached below is missing part
answer : Pauli's exclusion principle
Explanation:
The principle that was disobeyed is Pauli's exclusion principle this is because the Pauli's exclusion principle states that no two electrons can have the same set of quantum number.
In Box A the two electrons , have the same spin which means they have the same quantum number ( disobeys Pauli's exclusion principle )
Consider the pair of solvolysis reactions. Draw the organic products, then predict the type of substitution mechanism and compare the expected rates.
Answer:
See explanation
Explanation:
Solvolysis is a chemical reaction in which the solvent, such as water or alcohol, is one of the reagents and is present in great excess of that required for the reaction. The solvents act as or produce electron-rich atoms or groups of atoms (nucleophiles) that displace an atom or group in the substrate molecule(Encyclopedia Britannica).
For the two reactions, the organic product is the same(the product is drawn in the second image attached). The both reactions occur by SN1 mechanism since the substrate is a tertiary alkyl halide. The nucleophile is CH3OH and the rate of reaction depends on the concentration of the alkyl halide and independent of the concentration of methanol present.
Therefore, changing the volume of the solvent has no effect on the rate of reaction. The two reactions proceed at exactly the same rate since the initial concentration of the alkyl halide is the same for both reactions.
The Coriolis effect is the deflection of winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere because of Earth's rotation. Lesson 2.09 True False
Answer:
True
Explanation:
The Coriolis effect is the deflection of winds to the right in the Northern Hemisphere and to the left in the Southern Hemisphere because of Earth's rotation. This statement is true.
What is Coriolis effect ?Circulating air is deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere as the Earth rotates on its axis. The Coriolis effect refers to this deflection.
Because of the rotation of the Earth, we experience an apparent force known as the Coriolis force. The wind is deflected to the right in the northern hemisphere and to the left in the southern hemisphere as a result of this.
There is no curving of the object's path as measured relative to the Earth's surface because there is no turning of the Earth's surface underneath a horizontally and freely moving object at the equator.
Thus, There is no Coriolis effect because the object's path is straight.
To learn more about the Coriolis effect, follow the link;
https://brainly.com/question/14290551
#SPJ6
Use stoichiometry to determine how many moles of O2 are needed
to completely react with 2.25 moles of C3H8. Please show your work
Answer:
11.25 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O
From the balanced equation above,
1 mole of C₃H₈ reacted with 5 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 2.25 moles of C₃H₈. This can be obtained as follow:
From the balanced equation above,
1 mole of C₃H₈ reacted with 5 moles of O₂.
Therefore, 2.25 moles of C₃H₈ will react with = 2.25 × 5 = 11.25 moles of O₂.
Thus, 11.25 moles of O₂ is needed for the reaction.
PLEASE HELP MEEEEEEEEEEEEEEEEEEEEEEE
Which state of matter consists of particles that are close together in a random pattern?
Gas
Liquid
Plasma
Solid
Answer: The answer is liquid
Explanation:
The state of matter consists of particles that are close together in a random pattern is liquid . Hence , Option (B) is correct.
What is States of matter ?
When energy is added or removed to matter, it changes state to form a state of matter.
A state of matter is defined as one of the ways in which matter can interact with itself to form a homogeneous phase.
Therefore , The state of matter consists of particles that are close together in a random pattern is liquid . Hence , Option (B) is correct.
Learn more about States of matter here ;
https://brainly.com/question/13233345
#SPJ2
Dinitrogen tetraoxide is a colorless gas that dissociates into nitrogen dioxide, a reddish brown gas.
a. True
b. False
Answer:
False
Explanation:
Disassociation of Dinitrogen tetraoxide is shown below -
N2O4(g) ⇌ 2NO2(g)
Nitrogen dioxide gas is deep red-orange in color. However, in presence of aerosols, this gas appears reddish-brown in color.
Hence the given statement is False
How many total moles of ions are released when 0.0341 moles of Na2HPO4 dissolves completely in water
Answer:
0.1023 moles
Explanation:
We have this reaction
Na2HPO4 → 2Na+ + NPO4-
1 mole gives us 3 ions
Na+ has 2 ions to it
NPO4 has 1 ion
2 + 1 = 3
We multiply 3 with the number of moles to get the answer to this question
3 x 0.0341
= 0.1023 moles
So we conclude that total moles released when dissolved in water is equal to 0.1023
what is an invasive species and how can it affect an ecosystem
Answer:
Here
Explanation:
An invasive species is an organism that causes ecological or economic harm in a new environment where it is not native. ... Invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats.